name top-level configure scope after the project file

... instead of the directory it resides in, to make it independent of
the user's fs layout. this makes logs more comparable, and little else.

Change-Id: I0ab3e968dad74ef86577f388c8ca1557e3c17ce4
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>

mkspecs/features/qt_configure.prf

@@ -1703,9 +1703,8 @@ defineTest(qtConfProcessOutput) {
     return()
 }
 
-c = $$basename(_PRO_FILE_PWD_)
-config.$${c}.dir = $$_PRO_FILE_PWD_
-cfgs = $$c
+config.$${TARGET}.dir = $$_PRO_FILE_PWD_
+cfgs = $$TARGET
 !isEmpty(_QMAKE_SUPER_CACHE_) {
     for (s, SUBDIRS) {
         config.$${s}.dir = $$_PRO_FILE_PWD_/$${s}